In a combine harvester and thresher the standing crop which has been cut and from which much of the grain has been separated is fed back to a shaking screen or reed which lines the stalks of the crop up parallel to each other and shakes any remaining grain from them. Such a harvester-thresher is described on pages 432-433 of The Way Things Work (Simon & Schuster: 1967). The straw rack with the shaking screens allows the straw to be formed into a neat windrow making baling easy and at the same time insures that all of the grain will be separated from the stalks.
It is known to provide distributing members above the straw rack at the forward end thereof. These distributing members are tines or wires which are displaceable transverse to the travel direction of the machine and are driven by a drum from which they extend radially so that they not only travel transverse to transport direction but also reciprocate up and down. Such an arrangement serves to loosen up the straw mass somewhat, but often allows wadded masses of straw to travel through the shaking screen, carrying with them valuable grain and making subsequent baling more difficult.